World War II was the biggest and deadliest war in history, involving over countries.

Sparked by Nazi Germany invading in 1939, the war dragged on for six years until the Allies defeated the Axis powers in 1945.

Due to , the U.S. was hesitant to get involved in WWII, until the conflict showed up at our doorstep.

The worldwide Great Depression of the 1930s took its toll in different ways throughout the world. In Europe, political power shifted to governments that wanted complete control of their people, like in Nazi Germany and Italy. In Asia, a resource-starved Japan began to expand and invaded China.

The United States, however, chose to withdraw from world affairs and concentrate on its own economic problems. believed that problems in the U.S. would be worsened by intervening in international affairs. Even after Hitler invaded Poland, President Roosevelt maintained U.S. , though he did indirectly support the British and the Allies in their fight against Nazi Germany by supplying them with American-made weapons and equipment through the program.

On December 7, 1941, the U.S. naval base in Pearl Harbor was attacked in one of the biggest military in the history of warfare. In less than two hours:

• Over 300 airplanes, 20 American naval vessels, including eight battleships, destroyed.

• More than 2,400 Americans died, including . Another 1,000 people were wounded.

The American people were outraged. Though diplomatic relations between the United States and Japan were , they had not yet broken off at the time of the attack. Instantly, the incident united the American people in a massive for war and strengthened American resolve to guard against any future lapse of military alertness.